Tandem bicycles for two or more riders arranged one behind the other are well known in the art. Typically, a standard tandem bicycle has a long wheelbase, much longer than a standard one person bicycle. The riders are arranged one behind the other with the front rider being in control of the steering of the bicycle. There is typically a second set of non-functional handlebars behind the front seat for the rear rider.
Standard tandem bicycles can be fast and a lot of fun, but they do have certain drawbacks. The long wheelbase of a tandem reduces the portability and maneuverability of the bicycle. The rear rider has no control over the steering of the bicycle, in fact many times the rear rider cannot even see over the front rider to look at the road ahead. This reduces the rear rider's control and sense of participation and, therefore, his or her fun in riding the bicycle. The rear rider is reduced to a mere "engine room" rather than an active participant in riding. Another disadvantage is the head-to-tail arrangement of the riders. Besides reducing the rear rider's view, it also separates the riders so that they cannot interact or communicate easily. This is a serious detriment for social or leisure riding. In fact, riders on a tandem bicycle may feel more isolated from one another than if they were riding side-by-side on separate standard bicycles.
Although the long wheelbase makes it somewhat awkward, a standard tandem bicycle can be ridden by a single rider in the front position; however, it cannot be ridden by a single rider in the rear position.
Close-coupled tandem bicycles are different from standard tandem bicycles in that the riders are situated much closer to one another, arranged front-to-back rather than head-to-tail. This arrangement allows the wheelbase of the bicycle to be significantly shortened. The shortened wheelbase improves the portability and maneuverability of the bicycle, while it brings the riders closer together allowing more interaction between them.
The simplest close-coupled tandem bicycles are, in fact, converted single-person bicycles. U.S. Pat. Nos. 4,002,351 and 4,029,326 both describe ways to convert a single-person bicycle into a close-coupled tandem bicycle by placing a second seat and a pedal crank behind the seat and pedal crank of the front rider. Both of these bicycles are made without any handlebars for the rear rider. The rear rider must support and balance him or herself by holding onto the front rider. This arrangement would be comfortable only for short rides and it gives no steering control to the rear rider.
German patent DE 3234183 describes a close-coupled tandem bicycle with a foldable handlebar for the rear rider that is attached to the frame in front of the front rider. The rear rider reaches around the front rider and grips the handlebar. This give the rear rider somewhere to hold onto, improving comfort and balance, but still gives no steering control to the rear rider.
Another German patent DE 3213659 addresses the problem of visibility from the rear seat of the tandem bicycle by raising the rear seat and pedal crank above the height of the front seat so that the rear passenger has a clear view over the head of the front passenger. This also allows for closer seating and a shorter wheelbase, as with a close-coupled tandem, but the arrangement is inflexible and it does not make any provision for steering control by the rear rider.
U.S. Pat. No. 3,191,965 describes a close-coupled tandem bicycle that has two pedal cranks, but one elongated seat for both riders, similar to the "banana seats" that were popular on children's bicycles of that time. The bicycle has an elongated handlebar with two sets of handgrips that allow either the front passenger or the rear passenger or both to control the steering. Because there is only a single seat and a single handlebar, the riders cannot both adjust the bicycle for their individual comfort. Unless the riders are precisely the same size, one or the other of them is bound to be uncomfortable with the seat position and/or the handlebar position.
What is lacking in the prior art is a close-coupled tandem bicycle which allows steering control by the front or the rear passenger and which is completely adjustable for the individual comfort of each of the passengers and for the desired degree of closeness between them.